docs: def _draw_linenumber(self, posno, lineno):
          """
          Remember a line number drawable to paint later.
          """
          self._draw_text(
              self._get_linenumber_pos(posno),
              str(lineno).rjust(self.line_number_chars),
              font=self.fonts.get_font(self.line_number_bold,
                                       self.line_number_italic),
              fill=self.line_number_fg,
          )